Device for fuel and chemical production from biomass-sequestered carbon dioxide and method therefor

ABSTRACT

A process and apparatus for converting sequestered carbon to fuel, such as methane, and/or materials, such as fermentation substrates, biopolymers, bioplastics, oils, pigments, fibers, proteins, vitamins, fertilizers and animal feed. The apparatus comprises a deep well carbon-sequestering bioreactor coaxially located within a deep well anaerobic bioreactor. Carbon is sequestered into a photosynthetic biomass or a heterotrophic biomass, which is subsequently digested by an anaerobic biomass containing methanogenic microbes, whereby methane is a digestion product.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of Ser. No. 12/661,002,filed Mar. 9, 2010 which claims the benefit of U.S. Provisional PatentApplication No. 60/209,929, filed Mar. 12, 2009, and both of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

Greenhouse gases (GHG) are proven to accumulate in the atmosphere due tomanmade sources including burning of fossil fuels. Carbon dioxide (CO₂)is implicated as the GHG of most concern by the United Nations and othersuch organizations, and the buildup of GHG in the atmosphere is possiblylinked to rising global temperatures, increasing acidity in the oceans,increased growth of allergic weeds, and other deleterious global-scaleproblems. Accordingly, there is great interest in development of devicesand methods for sequestration of CO₂, as well as converting thesequestered carbon to useful materials, such as fuels and chemicalproducts.

SUMMARY OF THE ILLUSTRATED EMBODIMENTS

This invention generally relates to systems, devices and methods ofremoval and sequestration of CO₂ from the atmosphere, flue gases andeffluent of industrial facilities, such as but not limited to powerplants, landfills, ethanol plants, chemical plants, and the like, bypropagation of carbon-sequestering organisms, such as photosyntheticalgae, micro algae, cyanobacteria and the like that require lightenergy, nutrients, water and CO₂ to grow organic mass, such as biomass,and/or heterotrophic microorganisms that use chemical carbon, chemicalor light energy, nutrients and water to grow organic biomass. Thecarbon-sequestering biomass generated as a result of carbonsequestration is anaerobically digested to generate methane (CH₄).Additionally or alternatively, the additional carbon-sequesteringbiomass generated can be harvested for use as raw material forbiopolymers, bioplastics, biodiesel, and the like, with the extractionwaste being anaerobically digested to generate methane.

In a first embodiment, a device for production of methane and chemicalsfrom sequestered carbon is provided. The device include an apparatus forproviding a source of carbon; a first processing chamber that isconfigured and arranged to receive water, the carbon and a biomass,wherein the biomass metabolizes at least a portion of the carbon so asto produce additional biomass; and a second processing chamber that isin fluid flow communication with the first processing chamber, and isconfigured and arranged for substantial anaerobic digestion at least aportion of the biomass while in the second chamber, such that methane isa digestion product.

In a further embodiment, the device includes a methane collectionapparatus associated with the second processing chamber.

In a further embodiment, the device includes a water and nutrientdelivery system associated with the first processing chamber.

In a further embodiment, the device includes a carbon dissolving anddistributing device for dissolving the carbon in at least one of waterflowing into the first processing chamber and water in the firstprocessing chamber.

In a further embodiment, the carbon is carbon dioxide.

In a further embodiment, the carbon is chemical carbon.

In a further embodiment, the biomass is a photosynthetic biomasscomprising an organism selected from the group consisting of algae andcyanobacteria.

In a further embodiment, the biomass is a heterotrophic biomasscomprising an organism selected from the group consisting ofmicro-algae, yeast and bacteria.

In a further embodiment, the first processing chamber includes a firstzone that is configured and arranged for growth of a photosyntheticbiomass and a second zone that is configured and arranged for growth ofa heterotrophic biomass. In a still further embodiment, the first andsecond zones are in fluid flow communication with each other.

In a further embodiment, the first processing chamber is coaxiallylocated within the second processing chamber.

In a further embodiment, the first processing chamber includes anelongated cylindrical shaft having upper and lower ends, and an LEDlight array located in the shaft. In a still further embodiment, thedevice includes a mixer located in the shaft. In another furtherembodiment, the first processing chamber is configured and arranged tosubject the biomass to pressure greater than atmospheric pressure. Instill another further embodiment, the upper end of the first processingchamber is in fluid flow communication with the second process chamber,such that overflow from the first chamber flows into the second chamber.

In a further embodiment, the second processing chamber includes anelongated cylindrical outer shaft with upper and lower ends, anelongated cylindrical middle shaft with upper and lower ends and that iscoaxially located within the outer shaft, and plurality of methanogenicbacteria located therein.

In a further embodiment, a substantial portion of the first and secondprocessing chambers extends vertically into the ground.

In a further embodiment, the biomass is algae and the device includes alight source located in the first processing chamber, where the lightsource is LEDs having a frequency that tends to promote growth of thealgae. In a still further embodiment, the first processing chamber isconfigured and arranged to subject the algae to a pressure greater thanatmospheric pressure.

In a further embodiment, the biomass is a heterotrophic biomass, thecarbon source is at least one of organic chemicals, sewage, wastewater,manure and industrial effluent, and the first processing chamberincludes an elongated cylindrical shaft having upper and lower ends. Ina still further embodiment, the device includes a mixer located in theshaft. In a still further embodiment, the heterotrophic biomass isphotosynthetic and the first processing chamber includes a light sourcehaving a frequency that tends to promote growth of the heterotrophicbiomass.

In a further embodiment, the device includes a physical-chemicaltreatment apparatus in communication with the first and secondprocessing chambers; wherein the physical-chemical treatment apparatusreceives a quantity of biomass from the first processing chamber,processes the received biomass to generate at least one product and aresidual biomass; and the second processing chamber receives theresidual biomass from the physical-chemical treatment apparatus. In astill further embodiment, the first processing chamber includes a lightsource; the carbon source is at least one of sewage, waste water,manure, and industrial effluent; and the at least one product isselected from the group consisting of a fermentation substrate, abiopolymer, a bioplastic, an oil, a pigment, a fiber, a protein, avitamin, a fertilizer and an animal feed. In a still further embodiment,the first processing chamber is configured and arranged to subject tobiomass to a pressure greater than atmospheric pressure.

In a second embodiment, a deep well bioreactor is provided forproduction of methane from carbon dioxide. In this embodiment, thedevice includes an anaerobic digester, including an elongated outershaft having upper and lower ends; an elongated middle shaft generallycoaxially located within the outer shaft, and having upper and lowerends, wherein the lower end of the middle shaft is in fluid flowcommunication with the lower end of the outer shaft; a methanecollection apparatus in flow communication with upper end of the outershaft; a plurality of methanogenic microorganisms located within themiddle and outer shafts, for substantial anaerobic digestion of acarbon-sequestering biomass, whereby methane is a digestion product; anda biomass incubator generally coaxially located within the middle shaftof the anaerobic digester, the incubator including an elongatedcylindrical inner shaft having an interior and upper and lower ends,wherein the upper end of the biomass incubator is in fluid flowcommunication with the upper end of the middle shaft of the anaerobicdigester; a carbon inlet apparatus in communication with the interior ofthe elongated cylindrical inner shaft, and configured and arranged toprovide at least some carbon distribution to water located in theinterior of the inner shaft; and a carbon-sequestering biomass locatedin the interior of the inner shaft, wherein the carbon-sequesteringbiomass metabolizes at least a portion of the provided carbon so as toproduce additional carbon-sequestering biomass, and thereafter thecarbon-sequestering biomass is at least partially converted to methanein the anaerobic digester.

In a further embodiment, the device includes at least one of a pluralityof LED lights located in the interior of the inner shaft; and a mixerlocated in the interior of the inner shaft.

In a further embodiment, the biomass incubator further includes anutrient delivery apparatus in communication with the interior of theinner shaft. In a still further embodiment, the nutrient deliveryapparatus includes at least one of a nutrient inlet and a water inlet influid communication with the inner shaft. In a still further embodiment,the carbon-sequestering biomass includes a plurality of photosyntheticmicroorganisms selected from the group consisting of algae andcyanobacteria. In a further embodiment, the device includes a pluralityof LED lights that have a frequency that tends to promote growth of thephotosynthetic microorganisms.

In a further embodiment, the carbon-sequestering biomass includes aplurality of heterotrophic microorganisms selected from the groupconsisting of micro-algae, yeast and bacteria.

In a further embodiment, the plurality of methanogenic microorganisms isselected from the group consisting of Methanosarcina spp andMethanothrix spp.

In a further embodiment, at least a portion of the device is buried andextends vertically into the ground.

In a third embodiment, a method for producing methane from carbondioxide is provided and includes the steps of exposing a photosyntheticbiomass to carbon dioxide, light and nutrients; allowing thephotosynthetic biomass to metabolize at least some of the carbondioxide, whereby additional photosynthetic biomass is produced;thereafter mixing a portion of the photosynthetic biomass with amethanogenic biomass; and allowing the methanogenic biomass toanaerobically digest the portion of the photosynthetic biomass, wherebymethane is produced as a digestion product.

In a further embodiment, the method includes collecting the methaneproduced.

In a further embodiment, the method includes providing water to thephotosynthetic biomass.

In a further embodiment, the method includes exposing the photosyntheticbiomass to pressure greater than atmospheric pressure.

In a further embodiment, the method includes dissolving carbon dioxidein water and distributing the carbon dioxide-laden water through thephotosynthetic biomass.

In a further embodiment, the method includes disposing a plurality ofLED lights within the photosynthetic biomass. In a still furtherembodiment, the method includes exposing the photosynthetic biomass to apressure greater than atmospheric pressure.

In a further embodiment, the method includes mixing the photosyntheticbiomass.

In a further embodiment, the method includes selecting a photosyntheticmicroorganism selected from the group consisting of algae andcyanobacteria.

In a further embodiment, the method includes flowing the portion of thephotosynthetic biomass into the methanogenic biomass.

In a further embodiment, the method includes selecting a methanogenicmicroorganism from the group consisting of Methanosarcina spp andMethanothrix spp.

In a further embodiment, the method includes allowing the methanogenicbiomass to anaerobically digest the portion of the photosyntheticbiomass with a two-phase methane fermentation process, wherein the firstphase is acidogenic fermentation and the second phase is methanogenicfermentation.

In a further embodiment, the method includes receiving carbon dioxidefrom a carbon dioxide source.

In a further embodiment, the method includes growing biomasshydroponically.

In a fourth embodiment, a method for production of methane from carbondioxide in a deep well bioreactor is provided, including the steps ofproviding a plurality of methanogenic microorganisms located in ananaerobic digester; providing a carbon-sequestering biomass located inan incubator located coaxially within the anaerobic digester, whereinthe incubator is in fluid flow communication with the anaerobicdigester; mixing a carbon source with the carbon-sequestering biomass;allowing the carbon-sequestering biomass to metabolize at least aportion of the carbon of the carbon source, whereby additionalcarbon-sequestering biomass is produced; mixing a portion of thecarbon-sequestering biomass with the plurality of methanogenicmicroorganisms; and allowing the methanogenic microorganisms tosubstantially anaerobically digest at least a portion of thecarbon-sequestering biomass, whereby methane is produced.

In a further embodiment, the method includes providing a plurality ofmethanogenic microorganisms selected from the group consisting ofMethanosarcina spp and Methanothrix spp.

In a further embodiment, the method includes providing a plurality ofcarbon-sequestering microorganisms selected from the group consisting ofphotosynthetic algae, cyanobacteria, heterotrophic micro-algae, yeastand bacteria.

In a further embodiment, the method includes mixing at least one ofnutrients and water with the carbon-sequestering biomass.

In a further embodiment, the carbon-sequestering biomass is aphotosynthetic biomass; and the method includes comprises exposing thephotosynthetic biomass to at least one of visible light and infra redlight via a plurality of LEDs located within the incubator. In a stillfurther embodiment, the method includes exposing the photosyntheticbiomass to a pressure greater than atmospheric pressure.

In a further embodiment, the method includes flowing the portion of thecarbon-sequestering biomass into the plurality of methanogenicmicroorganisms.

In a further embodiment, the method includes allowing the methanogenicbiomass to anaerobically digest the portion of the carbon-sequesteringbiomass with a two-phase methane fermentation process, wherein the firstphase is acidogenic fermentation and the second phase is methanogenicfermentation.

In a further embodiment, the method includes collecting the methaneproduced.

In a fifth embodiment, a method for producing a product from acarbon-sequestering biomass in a deep well bioreactor is provided,including the steps of providing a source of carbon; incubating thesource of carbon with a biomass, wherein the biomass metabolizes atleast a portion of the carbon of the carbon source so as to produceadditional biomass; and subjecting at least a portion of the biomass tophysical-chemical treatment, so as to produce a product selected fromthe group consisting of a fermentation substrate, a biopolymer, abioplastic, an oil, a pigment, a fiber, a protein, a vitamin, afertilizer and an animal feed.

In a further embodiment, the method includes providing a carbon sourceselected from the group consisting of organic chemicals, sewage,wastewater, manure and industrial effluent; and providing aheterotrophic biomass.

In a further embodiment, the method includes providing a carbon sourceincluding carbon dioxide, and providing a light source; and providing aphotosynthetic biomass.

Some of the advantages of the present invention over the prior artinclude the following. The illustrated device and described methodsremove CO₂, a major greenhouse gas and an air pollutant, from any CO₂laden air stream, such as atmospheric air, combustion gases of powerplants, land fill gases, and the like, and transforms the CO₂ into aphotosynthetic biomass. Removal of the CO₂ is maximized by utilizing adeep well reactor, such as a bioreactor, which increases the solubilityof the CO₂ because of the higher temperature and pressure associatedwith deep well reactors. LED lights are used to provide consistent andcontrolled frequencies of visible and infra red light, whereby maximumphotosynthetic and growth rates can be achieved in return for the energyutilized to provide light. Furthermore, the illustrated device andmethods advantageously remove chemical carbon from effluents using aheterotrophic biomass, and transforms the chemical carbon into methane.Incidental metals are also removed from industrial and/or ground waters,when they are used as an influent to the photosynthetic reactor by meansof adsorption to the biomass. Furthermore, by configuring the device asa deep well reactor, land requirements are substantially reducedrelative to the land requirements of above-ground systems.

Useful products are generated by the illustrated embodiments. Forexample, methane (CH₄), which can be used to generate energy and/or as araw material, is generated by anaerobic digestion of thecarbon-sequestering biomass. In another example, at least a portion ofthe carbon-sequestering biomass can be recovered and used for rawmaterials, such as fiber, animal feed, and fertilizer, organicchemicals, such as recovered oils, purified substances such asnutrients, vitamins, biopolymers and bioplastics, and pigments, and/oran industrial feedstock, such as fermentation substrate. Conversion ofCO₂ into methane is enhanced due to the recirculation of a portion ofthe generated biogas into the digestion liquor. Due to the highpressure, such as pressure greater than atmospheric pressure, in thedeep well reactor, solubility of CO₂ in the digestion liquor isincreased and more CO₂ is converted to methane by anaerobic bacteria.Furthermore, Certified Emission Reductions (CERs) are generated, whichcan be traded on global carbon exchange markets, as determined by theKyoto Protocol and pending climate change conventions and agreements.

Various objects and advantages of this invention will become apparentfrom the following description taken in conjunction with theaccompanying drawings wherein are set forth, by way of illustration andexample, certain embodiments of this invention.

The drawings constitute a part of this specification and includeexemplary embodiments of the present invention and illustrate variousobjects and features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially schematic drawing of a deep well bioreactor forcarbon sequestration and methane production with portions exposed toshow detail thereof.

FIG. 2 is a cross section of the bioreactor, taken along line 2-2 ofFIG. 1.

FIG. 3 is a flow diagram of the inputs and output of a method for carbonsequestration and methane production in a deep well bioreactor.

FIG. 4 is a flow diagram of some treatments of a carbon-sequesteringbiomass.

DETAILED DESCRIPTION OF THE INVENTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention, which may be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present invention in virtually anyappropriately detailed structure.

In the illustrated embodiments, production of methane from a carbonsource is accomplished in two stages, such as processes or steps. Insome embodiments, the carbon source is CO₂, such as is found inatmospheric gases, flue gases, and the like. In some embodiments, thecarbon source is chemical carbon. Suitable chemical carbon sourcesinclude but are not limited to organic chemicals, sewage, waste water,manure, and industrial effluent.

In the first stage, carbon, such as CO₂ or chemical carbon, issequestered in carbon-sequestering microorganisms. In circumstanceswherein the carbon source is CO₂, the carbon-sequestering microorganismsare generally photosynthetic, such as algae, micro algae, cyanobacteria,hydroponic plants or plant fragments and the like. Such photosyntheticmicroorganisms metabolize the CO₂, such as in the presence of lightenergy, and multiply or grow and increase the biomass, such asbiological material derived from living, or recently living organisms,especially micro- or macro-algae, bacteria, yeast, and callus, or higherplants that can be grown individually in a hydroponic state, therebygenerating or producing additional photosynthetic microorganisms, suchthat the biomass is expanded. In circumstances wherein the carbon sourceis chemical carbon, the carbon-sequestering microorganisms areheterotrophic, and may or may not be photosynthetic. The heterotrophicmicroorganisms metabolize the chemical carbon and multiply and increasethe carbon-sequestering biomass, thereby generating additionalheterotrophic microorganisms. Useful heterotrophs include but are notlimited to micro-algae, such as Chlorella protothecoides, Euglenagracilis, Cyclotella cryptica, Monoraphidium minutum, yeast, such asSacchromycese cerevisiae, and bacteria, such as Bacillus subtilis.

In some embodiments, in the second stage, the sequestered carbon isconverted into methane when at least some of the carbon-sequesteringmicroorganisms of the first stage, such as a portion of the expandedbiomass, are anaerobically digested, such as by a two-phase process,wherein acidogenic fermentation is the first phase and methanogenicfermentation is the second phase, to produce methane. It is foreseenthat other microorganism driven processes, of types well known in thedigestion industry, could be utilized to produce methane from thebiomass. Both stages, such as carbon sequestration and methanegeneration, take place in a generally vertical, circular, deep well,underground bioreactor, such as described herein.

In some embodiments, prior to the second stage, at least a portion ofthe carbon-sequestering biomass is processed using physical-chemicalprocesses, to produce chemicals, such as but not limited to fermentationsubstrates, biopolymers, bioplastics, oils, pigments, fiber, proteins,vitamins, fertilizer, and animal feed, such as described below. Aresidue, generated by the physical-chemical processes, is subjected tothe second stage, to produce methane from the residue.

FIGS. 1-2 illustrate a first embodiment of a device 100 for producingmethane from a carbon source, such as but not limited to CO₂ andchemical carbon. The device includes a first processing chamber 102,such as an incubator, reactor, bioreactor, inner chamber, photobioreactor, referred to herein as a carbon-sequestering biomassincubator, and a second processing chamber 104, such as an incubator,reactor, bioreactor, and referred to herein as an anaerobic digester,that includes a middle chamber 106 and an outer chamber 108. Thecarbon-sequestering biomass incubator 102 is in fluid flow communicationwith the anaerobic digester 104. For example, at least some of the fluidin the carbon-sequestering biomass incubator 102 flows into theanaerobic digester 104. The device also includes a carbon source inletapparatus 120 for supplying, delivering and/or distributing carbon tothe carbon-sequestering biomass incubator 102, a collection apparatus122, such as methane collection apparatus, biogas handling system, forcollecting the methane product from the anaerobic digester 104, anoptional light source 124 located within the first processing chamber102, and an optional mixing apparatus 126 (shown in phantom) alsolocated within the first processing chamber 102.

At least a portion of the device 100 extends below the ground. Inpreferred embodiments, a substantial portion of the device 100, such asa substantial portion of the carbon-sequestering biomass incubator 102and of the anaerobic digester 104, extends generally vertically into theground. Extending the device below ground level increases the pressurewithin the under-ground portion of the device to a pressure greater thanatmospheric pressure (at ground level). Advantageously, higher pressuresincrease the solubility of the CO₂ in the fluid. Consequently, whenunder pressure, the increased CO₂ concentration increases the rate ofsequestration, such as by the photosynthetic microorganisms, andadditionally or alternatively increases the rate of conversion of thesequestered CO2 to methane. In some embodiments, at least a portion ofthe device 100 extends from between about 50, 100, 200, 300, 400, 500,600, 700, 800, 900, and 1000 meters and about 1100, 1200, 1300, 1400,1500, 1600, 1700, 1800, 1900, and 2000 meters or more into the ground.In some embodiments, the device 100 extends from between about 0.25,0.5, 0.75, and 1.0 miles and about 1.25, 1.5, and 1.75 miles or moreinto the ground. Additionally, the device 100 includes an inner reactor,such as the carbon-sequestering biomass incubator 102, and an outerreactor, such as the anaerobic digester 104. In some embodiments, theinner reactor 102 has a diameter of from between about 1, 2, 3, or 4feet and about 6, 7, 8 or 9 feet or more. In some embodiments, the outerreactor 104 has a diameter of from between about 10, 11, 12 or 13 feetand about 14, 15, 16, 17 or 18 feet or more.

In some embodiments, the carbon-sequestering biomass incubator 102, suchas the first processing chamber or first reactor 102 is a photobioreactor, such as for the incubation, growth and/or expansion of aphotosynthetic carbon-sequestering organism, such as an algae orcyanobacterium, or optionally a photosynthetic heterotroph. A variety ofalgae and cyanobacterium known in the art can be used, such as describedherein. In this embodiment, the carbon-sequestering biomass incubator102 includes a light source 124, discussed in greater detail below, andis configured and arranged to receive one or more influents. Influentsreceived by the first chamber include at least one of, but not limitedto, water 130 (H₂O), nutrients 132, and a source of carbon, such as butnot limited to CO₂ dissolved in water by an apparatus 120 configuredtherefor, such as a CO₂ source apparatus, CO₂ inlet apparatus. In afurther embodiment, the carbon-sequestering biomass incubator 102subjects the photosynthetic, carbon-sequestering biomass therein toincreased pressure, such as a pressure greater than atmospheric pressureat ground level, in the presence of light 124.

In some embodiments, the carbon-sequestering biomass incubator 102, suchas the first processing chamber or a first reactor 102, is aheterotrophic bioreactor, such as for the incubation, growth and/orexpansion of a heterotrophic carbon-sequestering organism. Incircumstances in which the carbon-sequestering biomass includesheterotrophs, the carbon source is chemical carbon, such as describedelsewhere herein. In this embodiment, the carbon-sequestering biomassincubator 102 may include a light source 124, such as for photosyntheticheterotrophs, and is configured and arranged to receive one or moreinfluents. Influents received by the first chamber include at least oneof, but not limited to, water 130 (H₂O), nutrients 132, and a source ofcarbon, such as but not limited to chemical carbon dissolved in water byan apparatus 120 configured therefor, such as the carbon sourceapparatus or a carbon inlet apparatus. In a further embodiment, thecarbon-sequestering biomass incubator 102 subjects the heterotrophic,carbon-sequestering biomass therein to increased pressure, such as apressure greater than atmospheric pressure at ground level. In someembodiments, the heterotrophic biomass is also photosynthetic, and theincubator 102 includes a suitable light source to increase or promotegrowth of the biomass.

Upon initial use, or first start up, of the device 100, thecarbon-sequestering biomass incubator 102 receives an innoculum, orinitial culture, of a suitable carbon-sequestering biomass, such as thealgae, cyanobacterium, or heterotrophic microorganism. During deviceoperation, the carbon-sequestering biomass metabolizes at least aportion of the carbon received, such as an influent, so as to produceadditional carbon-sequestering biomass, or the biomass expands, grows ormultiplies, which is then used to generate methane in the anaerobicdigester 104, such as the second processing chamber. In somecircumstances, a portion of the carbon-sequestering biomass is harvestedfor use as raw materials, such as fiber, animal feed and/or fertilizer,for production of organic chemicals, such as recovered oils, purifiedsubstances such as nutrients, vitamins, biopolymers and bioplastics, andpigments, and for industrial feedstock, such as a fermentationsubstrate, and as describe below, with reference to FIG. 4.

The carbon-sequestering biomass incubator 102 is generally coaxiallylocated within the middle shaft 106, such as the middle chamber, mixingchamber or shaft, of the anaerobic digester 104. As shown in FIG. 1, thecarbon-sequestering biomass incubator 102 is an elongated cylindricalinner shaft 134 having an interior 140, an upper end 142 and a lower end144. The upper end 142 of the carbon-sequestering biomass incubator 102is open, such that a portion 146 of the carbon-sequestering biomasstherein can flow out, such as by 146, of the upper end 142, such as overthe shaft's side wall 150, and into the middle shaft 106, such as themiddle chamber, of the anaerobic digester 104.

A carbon inlet apparatus 152, such as the CO₂ inlet apparatus 152, isassociated with and in communication with the interior 140 of thecarbon-sequestering biomass incubator 102, such as the elongatedcylindrical inner shaft. The carbon inlet apparatus 152 is configuredand arranged to provide at least some carbon, such as CO₂ or chemicalcarbon, distribution to water located in the interior of the elongatedshaft. For example, the carbon inlet apparatus 125 can include CO₂ gasdiffusers, jet nozzles, spargers, bubblers, educators, injectors and thelike that are spaced along the length of the carbon-sequestering biomassincubator 102 and deliver, or expel or inject, gaseous CO₂ 154, orgaseous or liquid chemical carbon, into the water, such as the liquorcontaining the biomass, within the interior 140 of thecarbon-sequestering biomass incubator 102, such that at least some ofthe carbon, such as CO₂ 154, becomes dissolved therein. It is noted thatfor convenience, in the Figures CO₂ 154 represents both CO₂ and chemicalcarbon. It is foreseen that the carbon can also be carried by, or mixedwith, water 130 entering the incubator 102 or supplemented thereby. Forexample, chemical carbon-laden sewage can be mixed with, or dilutedwith, water entering the incubator 102. Suitable sources of CO₂, such asa CO₂-laden air stream, include but are not limited to atmospheric air,combustion gases of power plants and manufacturing plants, land fillgases, and the like. Suitable sources of chemical carbon include but arenot limited to organic chemicals, sewage, waste water, manure andindustrial effluent.

In a further example, a plurality of spargers 154, such as is known inthe art, are spaced along the length of the carbon-sequestering biomassincubator's interior 140 and inject a controlled amount of carbon, suchas CO₂ laden air, as gaseous or liquid chemical carbon, into the cultureof algae, cyanobacteria or other biomass. Some of the carbon, such asdepicted as CO₂ 154, dissolves into or mixes with the culture media,such as water with nutrients, such as but not limited to nitrogen,phosphorus, and micronutrients therein. Some of the CO₂ 154 formsbubbles that rise to the surface and thereby generate a mixing action ofthe culture.

In some embodiments, the device 100 includes an optional mixingapparatus 126, located in the interior 140 of the carbon-sequesteringbiomass incubator 102, to facilitate mixing of the algal or bacterialculture (described in greater detail below). It is foreseen that mixingcan be provided by other devices that are well known in the art such ascirculating pump systems, flow diverters, incoming fluid spargers, jetnozzles, educators, pulse air mixers, paddles, and the like. While notwishing to be bound by theory, it is believed that carbon removal,especially CO₂ removal, and methane production is maximized by thedynamics of a deep well reactor, which increases the solubility of thecarbon, such as CO₂, due to the higher pressure, or pressure greaterthan atmospheric pressure, and higher temperature within the deep wellreactor.

The carbon inlet apparatus 152 injects the carbon into the interior 140of the carbon-sequestering biomass incubator 102. For example, a CO₂inlet apparatus 152 dissolves CO₂ 154 into a stream of water 130, thatis injected, such as flows, is delivered or provided to, into theinterior 140 of the carbon-sequestering biomass incubator 102. Inanother example, a chemical carbon inlet apparatus 152 mixed liquideffluents, such as from a manufacturing plant, with the water stream130, that is injected, such as flows, is delivered or provided to, intothe interior 140 of the carbon-sequestering biomass incubator 102. Thecarbon can be injected near, at or adjacent to the bottom 144 of theelongated inner shaft or inner chamber, or at any location along thelength of the shaft. For example, the carbon can be injected at alocation, such as within the shaft, from about 10%, 20%, 30%, 40% or 50%of the shafts length, with respect to the top end 142 of the shaft, toabout 60%, 70%, 90%, 85%, 90% or 95% of the shafts length or at evenlyor unevenly spaced locations therealong. Nutrients 132 can be added tothe carbon, such as by a nutrient delivery apparatus, prior toinjection. Injection of the carbon can also provide a mixing action tothe carbon-sequestering biomass culture.

A photon source is required to drive photosynthesis in photosyntheticorganisms. Accordingly, in some embodiments, the carbon-sequesteringbiomass incubator 102 includes a light source 124 sufficient forphotosynthesis by a photosynthetic carbon-sequestering biomass. In someembodiments, constant and controlled frequencies of visible and infrared light are made available to a photosynthetic biomass via a pluralityof LED lights 124, such as an LED light array, located in the interior140 of the elongated cylindrical shaft 134, such as the inner shaft. Forexample, a plurality of LED lights 124 can extend the length of theinner processing chamber 140. In a further example, strings of LEDs 124,such as LEDs attached to electrical wires, can be hung or suspendedwithin the inner chamber 134, such as a drop down, removable array ofLED lights. In another example, LEDs can be attached to the sides 156 orwalls of the chamber 134. The LEDs can be spaced along the length of thechamber 134, either singly or in clusters. In yet another example,strings of LEDs are suspended within the interior 140 of the chamber 134and LEDs are attached to the sides 156 of the chamber 134. In anotherexample, the light source 124 includes fiber optics. The light source124 is configured and arranged to provide visible light and optionallyinfra red light, such that the photosynthetic microorganisms can performphotosynthesis. It is noted that such LED lights are flashed on and off,in order to reduce energy consumption and to protect the photosynthesisfrom exhaustion. In preferred embodiments, the photosynthetic organismsreceive an amount to light for sufficient photosynthesis for an extendedperiod of time, whereby carbon sequestration by the photosyntheticcarbon-sequestering microorganisms is maximized.

An optional mixing apparatus 126 may be located in the interior 140 ofthe carbon-sequestering biomass incubator 102, such as within the innerchamber 136, whereby the liquor in this chamber is continuously mixedand the biomass is kept in suspension. The mixing apparatus 124 includesone or more mixing devices know in the art, such as but not limited tocirculating pump systems, flow diverters, incoming fluid spargers, jetnozzles, educators, pulse air mixers, paddles, and the like. The mixingdevices are spaced along the length of the chamber 136, such thatexposure of the microorganisms to light and nutrients is optimized formaximal carbon sequestration and the microorganisms, or biomass, aresuspended in the liquor. A portion of the suspended carbon-sequesteringmicroorganisms, such as algae, cyanobacteria or other biomass, overflow146, such as at the surface of the first chamber 102 or over wall 150,into the anaerobic digester 104.

A nutrient delivery apparatus 132 is associated with carbon-sequesteringbiomass incubator 102, such as the inner shaft. In some embodiments, thenutrient delivery apparatus 132 includes at least one of a nutrientinlet 174 and a water inlet 160 in fluid communication with thecarbon-sequestering biomass incubator 102, such as the interior chamber134. For example, the nutrient deliver apparatus 132 can include one ormore nozzles or valves located along the length of thecarbon-sequestering biomass incubator 102, for the injection ordelivery, such as inflow, of a nutrient-bearing water stream or culturemedium. Incidental removal of metals or other contaminants can beachieved if metal or contaminant-bearing water, such as the water 130,is used as an influent, generally by absorption of the metal/contaminantonto the carbon-sequestering biomass. Injection of the nutrients canassist in liquor mixing. For example, a nozzle or optionally mixer 126,shown in phantom, can be pointed generally downward, such as verticallywith respect to the inner shaft 134, or sideways, such as horizontallywith respect to the shaft 134, to create a local vortex or turbulence,for increased mixing at that location. In another example, a nozzle ispointed upward, to assist in a general upflow of the liquor.

The anaerobic digester 104, such as the second process chamber or outerreactor, is configured and arranged similarly to deep well bioreactorsknown in the art, such as but not limited to “VERTREAT” and “VERTAD”type bioreactors described in U.S. Pat. Nos. 5,650,070 and 6,468,429 toPollock and U.S. Pat. No. 4,217,211 to Crane, all of which areincorporated herein by reference. The anaerobic digester 104 includes anelongated cylindrical middle chamber 106, such as a middle shaft ormixing shaft, having upper and lower ends 162, 164 and an elongatedcylindrical outer shaft 108 having upper and lower ends 108 a, 170, andplurality of methanogenic bacteria 172, such as methanogenic biomass,located therein. The anaerobic digester 104 is configured and arrangedsuch that the methanogenic biomass 172 can circulate therethrough whilereceiving a portion of the carbon-sequestering biomass, such asoverflowing from the carbon-sequestering biomass incubator 102. Themiddle shaft 106, such as the middle chamber or mixing shaft, isgenerally coaxially located within the outer shaft 108, such as theouter chamber, and the carbon-sequestering biomass incubator 102 isgenerally coaxially located within the middle shaft 106, such thatoverflow from the carbon-sequestering biomass incubator 102 into thesecond chamber 104, such as into the middle shaft 106. The top ends 162,166 of the middle and outer shafts 106, 108 are in fluid flowcommunication with each other, such as open to each other. Similarly,bottom ends 164, 170 of the middle and outer shafts 106, 108 are influid flow communication with each other or open to each other. Themethanogenic microorganisms 172 located within the middle and outershafts 106, 108, such as the anaerobic digester 104, substantiallyanaerobically digest the carbon-sequestering biomass that flows into theanaerobic digester 104, whereby methane (CH₄) is a digestion product.

The top end 162 of the middle shaft 106, such as the mixing chamber, isopen to the carbon-sequestering biomass incubator 102, and a portion ofthe liquor in the carbon-sequestering biomass incubator 102, whichcontains some carbon-sequestering microorganisms, overflows 146 into themiddle shaft 106. The top end 162 is also open to the top end 166 of theouter shaft 108, such as the outer chamber, but fluid flowing from theouter shaft 108 and into the top end 162 of the middle shaft 106 doesnot substantially flow into the carbon-sequestering biomass incubator102. The liquor from the outer shaft 108 discharges through an outlet174.

While in the middle shaft 106 of the anaerobic digester 104, thecarbon-sequestering biomass, such as from the biomass incubator 102,undergoes the first phase of anaerobic digestion, stage, step orprocess, known as the acetogenic phase or acetogenic fermentation.During the acetogenic phase, enzymes secreted by certain bacteria, suchas Bacteroides, Butyrivibrio, Clostridium, Fusobacterium, Selonomonas,Peptococcus, Streptococcus, and the like, present in the liquor digestthe algae, cyanobacteria or other biomass, such as proteins, lipids andcarbohydrates therein, and generate acetate. In preferred embodiments,the acetogenic phase is carried out under substantially anaerobicconditions, using anaerobic bacteria.

The bottom end 164 of the middle shaft 106 is open to the bottom end 170of the outer shaft 108, and liquor in the middle shaft 106 flows 176,such as by underflow, into the outer shaft 108 and then in a generallyupward direction, toward the top end 166 of the outer shaft 108. Whilein the outer chamber 108, the effluent from the middle shaft 106undergoes the second phase of anaerobic digestion, called themethanogenic phase. Under anaerobic conditions, methanogenic bacteria172, such as methanogens, Methanosarcina spp. and/or Methanothrix spp.present in the digestion liquor convert the acetate (CH₃COOH) intomethane (CH₄). In general, the methanogens consume hydrogen (H₂) andCO₂, and reduce CO₂ as an electron accentor via the formyl, methenyl,and methyl levels through association with coenzymes, to finally producemethane (CH₄). The overall reaction can be expressed as:CH₃COOH→CH₄+CO₂. The resulting methane 173 is captured by a methanecapture device 122, such as a biogas handling system or a methanecollection apparatus, associated with the second processing chamber 104,such as is associated with the top end 170 of the outer shaft 108.

The treated effluent from the outer chamber 108 is generally removedinto an above ground dissolved air flotation unit, such as a clarifier180, where the biomass is separated from the liquor. A portion of theconcentrated biomass, such as sludge 182, is recirculated towards thebottom 164 of the middle shaft 106, such as by an inlet 184, so as toprovide a starting culture of acetogenic and methanogenic bacteria. Theexcess collected biomass or waste biosolids 186, such as from theanaerobic digester 104, is disposed of using methods known in the art,such as in fertilizer, burned for power, and the like. The biogasproduced during the digestion process is collected above ground, such asby the methane collection apparatus 122, and a portion 190 of the biogasis recirculated to both the middle and outer shafts 106, 108, to promotemixing and to increase the solubility of CO₂ in the digestion liquor. Insome embodiments, hydrogen (H₂) is also added, to increase conversion ofthe carbon-sequestering biomass into methane. While not wishing to bebound by theory, it is believed that conversion of the CO₂ in the biogasinto methane, such as causing a higher proportion of methane content inthe biogas, is enhanced by the recirculation of a portion 190 of thebiogas into the digestion liquor, due to the high pressure in the deepwell reactor, such as solubility of CO₂ in the digestion liquor isincreased and more CO₂ is converted to methane by the anaerobicbacteria.

FIG. 3 illustrates a method of using the device of the illustratedembodiments, namely a method for producing methane from a carbon sourcesuch as CO₂ or chemical carbon. In general, a device 100 of theillustrated embodiments is provided. This includes providing a pluralityof methanogenic microorganisms 172 located in an anaerobic digester 104and providing a carbon-sequestering biomass located in an incubator,such as carbon-sequestering biomass incubator 102, that is locatedcoaxially within the anaerobic digester 104, wherein the incubator 102is in fluid flow communication with the anaerobic digester 104. In someembodiments, the plurality of methanogenic microorganisms 172 providedis selected from the group consisting of Methanosarcina spp andMethanothrix spp. In some embodiments, the plurality of photosyntheticmicroorganisms provided is selected from the group consisting of algaeand cyanobacteria.

Carbon, such as a CO₂-laden air stream or a liquid chemical carbonstream, is mixed with the carbon-sequestering biomass. The carbon isreceived from a carbon source, such as the apparatus 120, such as byinjection through a carbon inlet apparatus 152 or the like. For example,the CO₂-laden air stream 120 can be derived from atmospheric air, fluegases, such as from power plants or manufacturers, and landfill gases.Additional influents, or inputs, include but are not limited tonutrients 132, water 130 and light 124. Water 130 can be supplied from avariety of sources, such as but not limited to freshwater, waste water,sea water, and ground water. In some embodiments, thecarbon-sequestering biomass is photosynthetic and constant andcontrolled light 124 are provided, such as by LEDs and/or fiberoptics.Alternatively or additionally, in some embodiments, thecarbon-sequestering biomass is subjected to a pressures that is greaterthat atmospheric pressure at ground level. The contents of the deep wellcarbon-sequestering bioreactor is mixed.

In another step of the method of the illustrated embodiment, thecarbon-sequestering biomass is allowed to metabolize at least a portionof the carbon, whereby additional carbon-sequestering biomass isproduced, such as the photosynthetic biomass grows, increases orexpands.

Next, a portion of the carbon-sequestering biomass is mixed with theplurality of methanogenic microorganisms in the anaerobic digester 104.For example, the portion of the carbon-sequestering biomass can flow,see FIG. 1, 146, into the plurality of methanogenic microorganisms 172,such as a methanogenic biomass, whereby the two biomasses become mixedor combined. One or more inputs can be added to the anaerobic digester104. For example, additional nutrients 194 and/or pH control chemicals196 can be added to the anaerobic digester 104, either continuously oron an as-needed basis. An amount of biogas 190 can be added, orrecirculated or recycled, such as to enhance mixing and to promote CO₂conversion into methane, as described elsewhere herein. An amount ofrecycled sludge 182, such as from effluent, can be added to theanaerobic digester 104, to replenish the methanogenic microorganisms172.

The methanogenic microorganisms 172 are allowed to substantiallyanaerobically digest the portion of the carbon-sequestering biomassmixed therein, whereby methane 173 is produced, such as a digestionproduct. Namely, the methanogenic biomass 172 is allowed toanaerobically digest the portion of the carbon-sequestering biomass witha two-phase methane fermentation process, wherein the first phase isacidogenic fermentation and the second phase is methanogenicfermentation, such as described elsewhere herein. As described elsewhereherein, in some embodiments, the methanogenic fermentation occurs at apressure greater than atmospheric pressure at ground level.

The methane 173 is contained in biogas, which is directed into a biogashandling system, such as the methane collection apparatus 122. Themethane 173 produced is collected, or separated from the biogas, by themethane collection apparatus 122. A portion 190 of the biogas isreturned or recycled to the anaerobic digester 104. While not wishing tobe bound by theory, it is believed that higher CO₂ concentrationspromote conversion of acetate to methane by the methanogenic bacteria172.

A variety of photosynthetic algae can be used with the presentinvention, such as but not limited to Macrocystis, such as Macrocystisangustifolia, Macrocystis integrifolia, Macrocystis laevis, andMacrocystis pyrifera, and Microcystis. While algae and cyanobacteria,also known as blue-green algae, blue-green bacteria or Cyanophyta, areuseful in the present invention, it is foreseen that micro algae, suchas Astaxinthin, Chlorella, Spirulina, Volvox, Prochlorococcus,Calothrix, and the like, could be utilized as well as hydroponicallygrown plants or plant fragments, or plant calli, such as a continuousplant cell culture. Further, some algae that sequester carbon as calciumcarbonate are useful in the present invention. These algae include, butare not limited to, Turbinaria ornata and Emiliania huxleyi. In someembodiments, the photosynthetic biomass is grown hydroponically usingmethods known in the art.

A variety of heterotrophic microorganisms can be used with the presentinvention, including but not limited to micro-algae, such as Chlorellaprotothecoides, Euglena gracilis, Cyclotella cryptica, Monoraphidiumminutum, yeast, such as Sacchromycese cerevisiae, and bacteria, such asBacillus subtilis.

A portion of the digestion liquor is collected in, or flows into or isdiverted into, a dissolved air flotation device, such as the clarifier180. The dissolved air flotation device separates the methanogenicbiomass, a portion of which, such as the sludge 182, is recycled to theanaerobic digester 104, such as by the inlet 184. The remainingmethanogenic biomass is disposed of as waste 186, such as biosolids. Afinal liquid effluent 192, such as water, is produced, which can beevaporated or disposed of as liquid waste using methods known in theart. Additionally, a portion of the effluent water 192 can be recycledback to the carbon-sequestering biomass incubator 102 and/or to theanaerobic digester 106, as the effluent water 192 contains nutrientsfrom the digestion process.

FIG. 4 illustrates another embodiment of the device 100, wherein atleast a portion of the carbon-sequestering biomass produced in thecarbon-sequestering biomass incubator 102 can be processed in up to twodifferent processes. Namely, the biomass produced can be directed tophysical-chemical treatment 200 and/or to an anaerobic digester 104. Insome embodiments, all of the biomass is directed to physical-chemicaltreatment 200. In some embodiments, a portion of the biomass, such asabout 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about35%, about 40%, about 45%, about 50%, about 60%, about 65%, about 75%,about 80%, about 85%, about 90% or about 95%, is directed tophysical-chemical treatment 200 while the remaining biomass is directedto the anaerobic digester 104. In still other embodiments, all of thebiomass is directed to the anaerobic digester 104. In a preferredembodiment, the device is configured and arranged such that the amountsof biomass directed to the physical-chemical treatment 200 and/or theanaerobic digester 104 can be modulated or otherwise changed oradjusted, such as depending upon changes in the needs of themanufacturer, the consumer, and the like.

In some embodiments, at least a portion of the carbon-sequesteringbiomass is removed from the carbon-sequestering biomass incubator 102for physical-chemical treatment 200. Suitable physical-chemicaltreatment include but are not limited to heating, acid and/or alkalitreatment, maceration, enzymatic degradation, solvent extraction withchemicals or critical CO₂, and cell disruption via extreme pressurechanges.

A number of products 202 can be produced from the photosynthetic biomassvia the physical-chemical treatment 200 described above. Exemplaryproducts include but are not limited to fermentation substrates,biopolymers and bioplastics, oil, pigments, fiber, protein, vitamins,fertilizer and animal feed. Generally, a residual biomass 204 isgenerated by the physical-chemical treatment 200 of the photosyntheticbiomass. The residual biomass 204 is directed to the anaerobic digester104, where it is digested as described above.

In yet another embodiment, the device 100 is a deep well, stand-alonganaerobic bioreactor or digester 104, such as described with regards toFIGS. 1 through 3. For example, with reference to FIGS. 1 and 2, thedevice 100 lacks the centrally located photosynthetic incubator portion102. Accordingly, in this embodiment, the device 100 receives a biomassfrom a separate device, rather than generating the biomass withinitself. For example, the biomass may be generated in a separatecarbon-capture device. In a further example, a photosynthetic biomassmay capture CO₂ in an incubator device integrated with a fluegas-handling system. After generation, the biomass is transferred fromthe incubator and into the anaerobic digester. Subsequently the receivedbiomass is anaerobically digested, such as described above. Methane maybe a digestion product, which may be captured and used as a fuel or araw material, such as is described elsewhere herein. In certainembodiments, the device 100 receives a stream of flue gas, such that theCO₂ present in the flue gas is directly converted into methane by theanaerobic process. Suitable microorganisms include, but are not limitedto, Methanobacterium thermoautotrophicum. It is noted that the pressureis increased within the deep well anaerobic digester 100. Accordingly,the solubility of the CO₂ from the flue gas is increased. The increasedconcentration of the CO₂ drives the conversion of the CO₂ to methane,such as by the M. thermoautotrophicum, towards improved production ofthe methane from the CO₂.

Example 1

An exemplary device 100 has a depth of about 500 ft into the ground andincludes an inner reactor, such as the carbon-sequestering biomassincubator 102, with a diameter of about 8 ft surrounded by an outerreactor, such as the anaerobic digester 104, with a diameter of about 15ft. The inner reactor contains algae with a concentration of about 5,000mg/dl of incubation liquid or medium. The algae grows at a rate of 2.3per day. The carbon content of the dry weight is about 50%. The inletgas, such as into the inner reactor, includes a CO₂ content of about15%. The CO₂ transfer efficiency, such as into the liquid, is about 70%.Of the CO₂ transferred into the liquid, the biomass takes up about 70%from the liquid. Thus, the CO₂ density is about 0.12 lb/ft³.

A number of materials are generated from the biomass in the innerreactor. From an amount of generated biomass, approximately 59% of thefuel and chemicals produced is proteins (dry weight), approximately 19%is fats and oils (dry weight), approximately 13% is carbohydrates (dryweight), and approximately 30% is residual biomass after productrecovery (dry weight).

The residual biomass, such as biomass left over after product recovery,is transferred to the outer reactor, such as the anaerobic digester 104,with a loading rate, such as biomass dry weight/reactor volume, of about0.5 lb/ft³. Approximately 35% of the transferred biomass is destroyedwith about 5 ft³ of methane produces per pound of biomass destroyed.

Example 2

An exemplary device 100, similar to that described in Example 1, above,includes a carbon-sequestering biomass incubator 102 with a volume of63,250 ft³ or 473,110 gal. The incubator 102 supports a biomassinventory of about 19,681 lbs and can produce about 45,267 lb of biomassper day. The produced biomass has a carbon content of about 22,634lb/day. About 82,990 lb of CO₂ is absorbed by the biomass per day. About118,557 lb of CO₂ is transferred into solution per day. The mass of theCO₂ in the inlet gas is about 169,367 lb per day, such as 1,411,391 ft³per day. Accordingly, the inlet gas volume is about 980 scfm.

The biomass generated undergoes physical-chemical treatment 200, such asheating, acid and/or alkali treatment, maceration, enzymaticdegradation, solvent extraction with chemicals or critical CO₂, and/orcell disruption via extreme pressure changes. Thus, about 26,708 lb (dryweight) of proteins is produced per day. Additionally, about 8,601 lb(dry weight) of fat/oil and about 5,885 lb (dry weight) of carbohydratesis produced per day. The residual biomass after product recover is about13,580 lb (dry weight) per day.

The residual biomass is transferred to the anaerobic digester 104. Theanaerobic digester has a volume of about 25,143 ft³, such as about188.069 gal. The digester 104 is fed biomass at a rate of about 13,580lb per day. The biomass fed requires a reactor design volume of about27,160 ft³. About 4,853 lb of biomass is destroyed per day, to generateabout 23,765 ft³ of methane per day. About 8,827 lb of biomass per dayis left for ultimate disposal, such as by incineration or in a landfill.

Example 3

An exemplary device 100 for production of methane from carbon dioxide isa deep-well device extending at least 500 feet into the ground. Thedevice 100 includes a CO²-providing apparatus, a photosyntheticbioreactor or incubator 102, for growing a photosynthetic biomass, andan anaerobic digester 104, for digesting at least a portion of thephotosynthetic biomass and generating methane as a digestion product.The incubator 102 is located coaxially within the anaerobic digester104, such that the upper end of the incubator 102 is in fluid flowcommunication with the upper end of the anaerobic digester 104. Theincubator 102 receives CO₂ from a CO₂ inlet, water and nutrients. Asource of light, sufficient for photosynthesis, is located within theincubator 102. The incubator is inoculated with a photosyntheticbiomass, which metabolizes at least a portion of the CO₂, so as toproduce additional photosynthetic biomass. A portion of thephotosynthetic biomass overflows into the digester 104. An anaerobicbiomass within the digester 104 substantially anaerobically digests thephotosynthetic biomass that overflows into the digester 104, andgenerates methane is a digestion product. The methane is collected by acollecting apparatus associated with the anaerobic digester.

Example 4

An exemplary device 100, similar to that described in Example 1, above,includes a heterotrophic carbon-sequestering biomass incubator 102 witha volume of 63,250 ft³, such as 473,110 gal. The incubator 102 supportsa biomass inventory of about 19,681 lbs and can produce about 45,267 lbof biomass per day. The produced biomass has a carbon content of about22,634 lb/day. About 82,990 lb of chemically derived carbon is absorbedby the biomass per day. About 118,557 lb of carbon is transferred intosolution per day. The mass of the carbon in the liquid carbon inlet isabout 169,367 lb per day.

The biomass generated undergoes physical-chemical treatment 200, such asheating, acid and/or alkali treatment, maceration, enzymaticdegradation, solvent extraction with chemicals or critical CO₂, and/orcell disruption via extreme pressure changes. Thus, about 26,708 lb (dryweight) of proteins is produced per day. Additionally, about 8,601 lb(dry weight) of fat/oil and about 5,885 lb (dry weight) of carbohydratesis produced per day. The residual biomass after product recover is about13,580 lb (dry weight) per day.

The residual biomass is transferred to the anaerobic digester 104. Theanaerobic digester has a volume of about 25,143 ft³, such as about188.069 gal. The digester 104 is fed biomass at a rate of about 13,580lb per day. The biomass fed requires a reactor design volume of about27,160 ft³. About 4,853 lb of biomass is destroyed per day, to generateabout 23,765 ft³ of methane per day. About 8,827 lb of biomass per dayis left for ultimate disposal, such as by incineration or in a landfill.

It is to be understood that while certain forms of the present inventionhave been illustrated and described herein, it is not to be limited tothe specific forms or arrangement of parts described and shown.

1-20. (canceled)
 21. An apparatus for converting sequestered carbondioxide to biomass comprising: a) a deep well bioreactor holding aquantity of water wherein a depth of the water is maintained at least at50 meters; b) a plant biomass located in the water; the plant biomassoperably using light in a photosynthesis reaction to convert carbondioxide to additional biomass; c) a light emitting array located withinthe water and extending from near a bottom to near a top thereof; and d)a carbon dioxide delivery system for operably delivering carbon dioxideto the water.
 22. The apparatus according to claim 21 wherein the waterdepth is between 100 and 2000 meters.
 23. The apparatus according toclaim 21 wherein the water level is greater than 1000 meters in depth.24. The apparatus according to claim 21 including a nutrient deliverysystem for operably delivering nutrients to the biomass.
 25. Theapparatus according to claim 21 including a fluid flow mechanism foroperably flowing the water through the well.
 26. The apparatus accordingto claim 21 wherein the bottom of the deep well includes a flow outletthat operably discharges water and biomass from the well.
 27. Theapparatus according to claim 26 including an anaerobic digester thatoperably receives biomass from the well outlet; and the digesterincluding a plurality of methanogenic microorganisms that operably atleast partially convert biomass into methane.
 28. The apparatusaccording to claim 21 wherein the light emitting array comprises a lightemitting diode device.
 29. The apparatus according to claim 21 whereinthe light emitting array comprises fiber optics.
 30. A method ofconverting carbon dioxide in methane utilizing the apparatus of claim 21comprising the steps of: a) flowing carbon dioxide from the carbondioxide delivery system into the water in the well; b) exposing thebiomass in the well to the light emitting array and the carbon dioxidein the well under pressure, so as to grow the additional biomass therebysequestering carbon dioxide in the biomass; and c) flowing theadditional biomass out of the well.
 31. The method according to claim 30including the step of: a) flowing the additional biomass into ananaerobic reactor with a plurality of methanogenic microorganismswherein a substantial amount of the additional biomass is converted tomethane; and b) recovering the methane.